Subway Terminal Building Plaster and Terra Cotta Preservation

Los Angeles, Los Angeles County,
California, USA

Seismic upgrades to the building structure required the intrusive removal of large areas of original decorative coffered ceiling and mandated the use of silicon rubber mould technology to manufacture new matching replacement units. Terra cotta capitals and columns were also involved in the rehabilitation of this space.

The Subway Terminal Building was the Grand Central Station of Los Angeles during the heyday of public light-rail transportation. A recent seismic upgrade required the manufacture and replacement of much of the original ceiling.

After the interurban trains ceased service in the late 50's, the public space of the Subway Terminal Building ceased functioning and fell into dis-use. The grand lobby and lower floors were subsequently leased by the Federal government and disastrously modified. The original terra cotta cladding on the columns was removed below 9 feet and a dropped ceiling system installed.

Fortunately the original terra cotta capitals and decorative plaster ceiling were left relatively untouched, with minor intrusions in the ceiling for the installation of the dropped ceiling system.

As our project began, the resulting ceiling and column arrangement was a severely truncated system of original surfaces below the height of 9 feet. As in so many of our projects, the removal of historic materials was completed only so far as the new changes warranted.

Since designated support columns were slated to receive structural improvements, we had to first remove existing decorative terra cotta elements in locations where this work was intended to take place.

During cleaning and restoration of these original terra cotta elements, we discovered that the capitals had been stained sometime in the past to render the beige surfaces dark, like an oak-colored stain. We were able to identify this staining technique and remove it using water-based cleaning agents.

All selectively removed terra cotta elements were carefully cut away to leave the outer decorative surfaces while removing up to 4" of inner material. This was done in order to be able to re-install the salvaged terra cotta elements over newly installed structural upgrades.

Here the remnant portions of the original terra cotta facade are being installed over the newly-installed concrete structural upgrades to the columns.

The same remove-and-replace technique was also used for engaged pilasters at the walls. Fortunately for the building the wall areas were not removed in the 70's but only covered over. This is something we frequently come across in our quest to restore old spaces: Efforts to cover over or alter original historic surfaces were usually engaged in only so far as was necessary. Thus, we frequently come across original historic building fabric under the layers of facade 'improvements' previously applied. It's likely that the former contractors followed the KISS principle and only removed what they absolutely had to.

Most of the column locations were similar to this image - all decorative plaster was removed within a radius of 4 feet to allow for structural upgrades.

This project was somewhat unique in that we were able to adhere to standard Historic Preservation principles - in this case making sure that removed sections of the original gypsum plaster ceiling were salvaged in such a manner as to be intact enough for re-installation. This was an especially difficult method to use since the original plaster ceiling units were much heavier than contemporary materials. A typical and easier solution not used for this project would have been to demo all original material and replace with newer lighter plaster.

Consequently, a great deal of labor was expended to repair and reinforce the original plaster units removed prior to structural work.

Original mounting points were reinforced with new plaster, structural enhancements were placed so as to improve the stability of the original plaster decorative units.

This image shows the original support grid with old plaster anchor spots still in place. This entire band around the perimeter of the work area was removed, salvaged and repaired, and re-installed in the original location, using the old support system in some locations, and using a new steel support system in others.

Here a salvaged ceiling coffer unit is being re-installed onto the newly fabricated black iron support system after structural work at the adjacent column has been completed.

This image shows a completed section of ceiling with coffered units and beam case re-installed. The project was unfortunately limited in scope and we were not able to complete the painting of the finished product. Hopefully a future tenant of this space will have the will and the resources to finish the job.

Run-molded sections such as this ogee corner are mitred prior to installation.

Here the coffered sections have been installed and the decorative rosettes await installation.

Imitating the original construction method, we made a mold of the original rosette design, and then made multiples of the rosettes for installation over the corners of decorative units. This allowed us to cover the supporting wires at the corners and intersections.

Phase I of the Red Line Terminal Lobby is complete and ready for the next stage of regeneration of this venerable LA landmark.